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ovs/lib/rtnetlink-route.c
Ethan Jackson ea83a2fcd0 lib: Show tunnel egress interface in ovsdb
This commit parses rtnetlink address notifications from the
kernel in order to display the egress interface of tunnels in the
database.

Bug #4103.
2011-01-04 12:35:59 -08:00

120 lines
3.5 KiB
C

/*
* Copyright (c) 2009, 2010 Nicira Networks.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <config.h>
#include "rtnetlink-route.h"
#include <arpa/inet.h>
#include <sys/socket.h>
#include <linux/rtnetlink.h>
#include <net/if.h>
#include "netlink.h"
#include "ofpbuf.h"
#include "rtnetlink.h"
static struct rtnetlink *rtn = NULL;
static struct rtnetlink_route_change rtn_change;
/* Parses a rtnetlink message 'buf' into 'change'. If 'buf' is unparseable,
* leaves 'change' untouched and returns false. Otherwise, populates 'change'
* and returns true. */
bool
rtnetlink_route_parse(struct ofpbuf *buf,
struct rtnetlink_route_change *change)
{
bool parsed;
static const struct nl_policy policy[] = {
[RTA_DST] = { .type = NL_A_U32, .optional = true },
[RTA_OIF] = { .type = NL_A_U32, .optional = false },
};
static struct nlattr *attrs[ARRAY_SIZE(policy)];
parsed = nl_policy_parse(buf, NLMSG_HDRLEN + sizeof(struct rtmsg),
policy, attrs, ARRAY_SIZE(policy));
if (parsed) {
const struct nlmsghdr *nlmsg;
const struct rtmsg *rtm;
nlmsg = buf->data;
rtm = (const struct rtmsg *) ((const char *) buf->data + NLMSG_HDRLEN);
if (rtm->rtm_family != AF_INET) {
return false;
}
change->nlmsg_type = nlmsg->nlmsg_type;
change->rtm_dst_len = rtm->rtm_dst_len;
change->rta_oif = nl_attr_get_u32(attrs[RTA_OIF]);
change->rta_dst = (attrs[RTA_DST]
? ntohl(nl_attr_get_be32(attrs[RTA_DST]))
: 0);
}
return parsed;
}
/* Registers 'cb' to be called with auxiliary data 'aux' with route change
* notifications. The notifier is stored in 'notifier', which callers must
* not modify or free.
*
* Returns 0 if successful, otherwise a positive errno value. */
int
rtnetlink_route_notifier_register(struct rtnetlink_notifier *notifier,
rtnetlink_route_notify_func *cb, void *aux)
{
rtnetlink_parse_func *pf = (rtnetlink_parse_func *) rtnetlink_route_parse;
rtnetlink_notify_func *nf = (rtnetlink_notify_func *) cb;
if (!rtn) {
rtn = rtnetlink_create(RTNLGRP_IPV4_ROUTE, pf, &rtn_change);
}
return rtnetlink_notifier_register(rtn, notifier, nf, aux);
}
/* Cancels notification on 'notifier', which must have previously been
* registered with rtnetlink_route_notifier_register(). */
void
rtnetlink_route_notifier_unregister(struct rtnetlink_notifier *notifier)
{
rtnetlink_notifier_unregister(rtn, notifier);
}
/* Calls all of the registered notifiers, passing along any as-yet-unreported
* address change events. */
void
rtnetlink_route_notifier_run(void)
{
if (rtn) {
rtnetlink_notifier_run(rtn);
}
}
/* Causes poll_block() to wake up when address change notifications are ready.
*/
void
rtnetlink_route_notifier_wait(void)
{
if (rtn) {
rtnetlink_notifier_wait(rtn);
}
}